feat: generate barrel index.ts for multi-contract sync (#20) (#42)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: satoshai-dev

.changeset/barrel-file.md

@@ -0,0 +1,5 @@
+---
+"@satoshai/abi-cli": minor
+---
+
+Generate barrel `index.ts` file when syncing multiple contracts

src/codegen.ts

@@ -33,3 +33,26 @@ export function defaultFilename(contractId: string, format: 'ts' | 'json', nameO
   const name = nameOverride ?? contractId.split('.').pop() ?? contractId;
   return `${name}.${format}`;
 }
+
+/**
+ * Convert a kebab-case (or already camelCase) string to camelCase.
+ */
+export function toCamelCase(name: string): string {
+  return name.replace(/-([a-z])/g, (_, c: string) => c.toUpperCase());
+}
+
+/**
+ * Generate a barrel `index.ts` that re-exports all ABIs.
+ *
+ * Each entry maps to: `export { abi as <name>Abi } from './<filename>.js';`
+ */
+export function generateBarrel(entries: { name: string; filename: string }[]): string {
+  const lines = entries
+    .map(({ name, filename }) => {
+      const exportName = `${toCamelCase(name)}Abi`;
+      const modulePath = `./${filename.replace(/\.ts$/, '.js')}`;
+      return `export { abi as ${exportName} } from '${modulePath}';`;
+    });
+
+  return [...lines, ''].join('\n');
+}

src/commands/sync.ts

@@ -3,7 +3,7 @@ import { mkdir, writeFile } from 'node:fs/promises';
 import { resolve, join } from 'node:path';
 import { loadConfig } from '../config.js';
 import { parseContractId, fetchContractAbi } from '../fetcher.js';
-import { generateTypescript, generateJson, defaultFilename } from '../codegen.js';
+import { generateTypescript, generateJson, defaultFilename, generateBarrel } from '../codegen.js';
 
 export const syncCommand = defineCommand({
   meta: {
@@ -25,6 +25,7 @@ export const syncCommand = defineCommand({
     await mkdir(outDir, { recursive: true });
 
     const failed: string[] = [];
+    const barrelEntries: { name: string; filename: string }[] = [];
     let synced = 0;
 
     for (const contract of config.contracts) {
@@ -40,18 +41,27 @@ export const syncCommand = defineCommand({
             ? generateTypescript(contract.id, abi)
             : generateJson(abi);
 
+        const resolvedName = contract.name ?? name;
         const filename = defaultFilename(contract.id, format, contract.name);
         const filepath = join(outDir, filename);
         await writeFile(filepath, output, 'utf-8');
         console.error(`Wrote ${filepath}`);
         synced++;
+        barrelEntries.push({ name: resolvedName, filename });
       } catch (err) {
         const message = err instanceof Error ? err.message : String(err);
         console.error(`Failed to sync ${contract.id}: ${message}`);
         failed.push(contract.id);
       }
     }
 
+    if (format === 'ts' && barrelEntries.length > 0) {
+      const barrelContent = generateBarrel(barrelEntries);
+      const barrelPath = join(outDir, 'index.ts');
+      await writeFile(barrelPath, barrelContent, 'utf-8');
+      console.error(`Wrote ${barrelPath}`);
+    }
+
     console.error(`\n${synced}/${config.contracts.length} contracts synced.`);
 
     if (failed.length > 0) {

tests/unit/codegen.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest';
-import { generateTypescript, generateJson, defaultFilename } from '../../src/codegen.js';
+import { generateTypescript, generateJson, defaultFilename, toCamelCase, generateBarrel } from '../../src/codegen.js';
 import { sampleAbi } from './fixtures.js';
 
 describe('generateTypescript', () => {
@@ -70,3 +70,49 @@ describe('defaultFilename', () => {
     expect(defaultFilename('standalone', 'ts')).toBe('standalone.ts');
   });
 });
+
+describe('toCamelCase', () => {
+  it('converts kebab-case to camelCase', () => {
+    expect(toCamelCase('amm-pool')).toBe('ammPool');
+  });
+
+  it('converts multi-segment kebab-case', () => {
+    expect(toCamelCase('nft-trait-v2')).toBe('nftTraitV2');
+  });
+
+  it('leaves already camelCase unchanged', () => {
+    expect(toCamelCase('ammPool')).toBe('ammPool');
+  });
+
+  it('leaves single word unchanged', () => {
+    expect(toCamelCase('token')).toBe('token');
+  });
+});
+
+describe('generateBarrel', () => {
+  it('generates re-exports with camelCase + Abi suffix', () => {
+    const result = generateBarrel([
+      { name: 'amm-pool', filename: 'amm-pool.ts' },
+      { name: 'nft-trait', filename: 'nft-trait.ts' },
+    ]);
+
+    expect(result).toBe(
+      [
+        "export { abi as ammPoolAbi } from './amm-pool.js';",
+        "export { abi as nftTraitAbi } from './nft-trait.js';",
+        '',
+      ].join('\n'),
+    );
+  });
+
+  it('uses .js extension in import paths', () => {
+    const result = generateBarrel([{ name: 'token', filename: 'token.ts' }]);
+    expect(result).toContain("from './token.js'");
+    expect(result).not.toContain('.ts');
+  });
+
+  it('handles single entry', () => {
+    const result = generateBarrel([{ name: 'my-contract', filename: 'my-contract.ts' }]);
+    expect(result).toBe("export { abi as myContractAbi } from './my-contract.js';\n");
+  });
+});

tests/unit/sync.test.ts

@@ -54,7 +54,8 @@ describe('syncCommand', () => {
     await runSync({ config: '/tmp/abi.config.json' });
 
     expect(mkdir).toHaveBeenCalledWith(resolve('./abis'), { recursive: true });
-    expect(writeFile).toHaveBeenCalledTimes(2);
+    // 2 ABI files + 1 barrel index.ts
+    expect(writeFile).toHaveBeenCalledTimes(3);
     expect(writeFile).toHaveBeenCalledWith(
       join(resolve('./abis'), 'token-a.ts'),
       expect.stringContaining('export const abi ='),
@@ -152,8 +153,8 @@ describe('syncCommand', () => {
       'Failed to sync: SP2.token-b',
     );
 
-    // Still wrote 2 successful contracts
-    expect(writeFile).toHaveBeenCalledTimes(2);
+    // 2 successful ABI files + 1 barrel
+    expect(writeFile).toHaveBeenCalledTimes(3);
   });
 
   it('throws when config not found', async () => {
@@ -192,4 +193,70 @@ describe('syncCommand', () => {
       'utf-8',
     );
   });
+
+  it('generates barrel index.ts for ts format', async () => {
+    mockConfig({
+      outDir: './abis',
+      contracts: [{ id: 'SP1.amm-pool' }, { id: 'SP2.nft-trait' }],
+    });
+    mockFetchSuccess(2);
+
+    await runSync({ config: '/tmp/abi.config.json' });
+
+    // 2 ABI files + 1 barrel
+    expect(writeFile).toHaveBeenCalledTimes(3);
+    expect(writeFile).toHaveBeenCalledWith(
+      join(resolve('./abis'), 'index.ts'),
+      expect.stringContaining("export { abi as ammPoolAbi } from './amm-pool.js';"),
+      'utf-8',
+    );
+    expect(writeFile).toHaveBeenCalledWith(
+      join(resolve('./abis'), 'index.ts'),
+      expect.stringContaining("export { abi as nftTraitAbi } from './nft-trait.js';"),
+      'utf-8',
+    );
+  });
+
+  it('does NOT generate barrel for json format', async () => {
+    mockConfig({
+      outDir: './abis',
+      format: 'json',
+      contracts: [{ id: 'SP1.token-a' }, { id: 'SP2.token-b' }],
+    });
+    mockFetchSuccess(2);
+
+    await runSync({ config: '/tmp/abi.config.json' });
+
+    // Only 2 ABI files, no barrel
+    expect(writeFile).toHaveBeenCalledTimes(2);
+    expect(writeFile).not.toHaveBeenCalledWith(
+      join(resolve('./abis'), 'index.ts'),
+      expect.any(String),
+      'utf-8',
+    );
+  });
+
+  it('barrel uses name alias when available', async () => {
+    mockConfig({
+      outDir: './abis',
+      contracts: [
+        { id: 'SP102V8P0F7JX67ARQ77WEA3D3CFB5XW39REDT0AM.amm-pool-v2-01', name: 'amm-pool' },
+        { id: 'SP2.nft-trait' },
+      ],
+    });
+    mockFetchSuccess(2);
+
+    await runSync({ config: '/tmp/abi.config.json' });
+
+    expect(writeFile).toHaveBeenCalledWith(
+      join(resolve('./abis'), 'index.ts'),
+      expect.stringContaining("export { abi as ammPoolAbi } from './amm-pool.js';"),
+      'utf-8',
+    );
+    expect(writeFile).toHaveBeenCalledWith(
+      join(resolve('./abis'), 'index.ts'),
+      expect.stringContaining("export { abi as nftTraitAbi } from './nft-trait.js';"),
+      'utf-8',
+    );
+  });
 });